Add support for including the path in the resource for Faraday

[samstarling]

I realised that I'd find it useful to have per-path reporting in Datadog for my Faraday traces: then I can see which endpoints on the services I'm calling are slow. I'd been talking to Fanny Jiang from Datadog support about this, and then I realised that I could make a pull request myself.

[samstarling]

@brettlangdon Do you happen to know if this repository is still maintained?

[brettlangdon]

@samstarling thank you for your contribution and my apologies for the late reply.

This issue is related to #278

As we have a good number of integrations that could also benefit from this change we are trying to think through a common solution that we can share across all of our integrations to give people the ability to have more control over how resources are set.

[samstarling]

@brettlangdon No problem – thanks for the fast reply! It's good to know you're looking at a generic solution to this. Please feel free to close this pull request, and I'll keep an eye on that issue. Good luck!

[brettlangdon]

@samstarling awesome, thanks!

I will close just to keep things focused on that other linked issue!